orthochromatic

adjective

or·​tho·​chro·​mat·​ic ˌȯr-thə-krō-ˈma-tik How to pronounce orthochromatic (audio)
1
: of, relating to, or producing tone values of light and shade in a photograph that correspond to the tones in nature
2
: sensitive to all colors except red

Word History

Etymology

International Scientific Vocabulary

First Known Use

1887, in the meaning defined at sense 1

Time Traveler
The first known use of orthochromatic was in 1887

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Cite this Entry

“Orthochromatic.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/orthochromatic. Accessed 12 Feb. 2026.

Medical Definition

orthochromatic

adjective
or·​tho·​chro·​mat·​ic ˌȯr-thə-krō-ˈmat-ik How to pronounce orthochromatic (audio)
1
: of, relating to, or producing tone values of light and shade in a photograph that correspond to the tones in nature
2
: sensitive to all colors except red
3
: staining in the normal way
orthochromatic tissue
an orthochromatic erythroblast
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